Apparatus for forming a flat narrow strip of parallel bonded filaments



June 1968 o. A. DRlCA-MINIERIS E L APPARATUS FOR FORMING A FLAT NARROWSTRIP OF PARALLEL BONDED FILAMENTS Filed Jan. 16, 1963 Z w F INVENTORSOSWALD A. DRlCA-MINIERIS ROBERT L. GARDNER United States Patent 0 Mpany, a corporation of Delaware Filed den. 16, 1963, Ser. No. 251,879 1Claim. {CL 156-441) This invention relates to the production of astrawlike article from nylon continuous filaments. More particularly,the present invention relates to a straw-like article made from parallelarranged multi-continuous filament nylon yarn bonded together by meansof a treatment with a bond-inducing agent of a particular class and to amethod of producing such article.

It is known to make artificial straw of viscose rayon by extruding aviscose spinning solution through an L- shaped orifice in a spinneret.Such product consists of a continuous heavy filament folded duringspinning and resembles a silk-like straw. In some cases there have beendisclosed multi-filament versions of this. Also, it is known to meltspin a narrow ribbon-like structure from nylon by using a slot of propersize and shape or by coalescing a plurality of melt spun filamentsbefore they are solidified. In either of these known melt spinningprocedures, a satisfactory narrow, fiat structure is expensive anddifi'icult to produce. Extremely costly melt spinning spinnerets arerequired. Moreover, it is difficult to arrange enough slots in aconventional spinneret blank to render the melt spinning economicallyfeasible.

It is an object of the present invention to provide as an article ofmanufacture a new and useful straw-like article from nylon continuousfilaments.

It is another object of the present invention to provide a new anduseful method of making an article simulating to some extent a straw andmade from parallel arranged multi-continuous nylon filaments.

Other objects of the invention may become apparent from the followingdescription.

In general, these objects are accomplished in the provision of astraw-like article or fillet composed of multicontinuous filament nylonyarn bonded together in a certain way. The yarn has a plurality ofsubstantially straight individual continuous filaments disposed in asubstantially parallelrclation with respect to each other and preferablyin a substantially parallel relation with respect to the long axis ofthe article. The article is elongated, narrow and flat, being laterallyat least two times as wide as it is thick and is composed of at leasttwo filaments. The longitudinal dimension of the narrow, fiat articlecan be any suitable length. While there is no definite upper limit forthe denier of the article with bands having deniers in excess of amillion being contemplated, the denier of the article for practicalreasons should be at least 15. It is preferred that the yarn from whichthe article is made have little or no twist, although the yarn canexhibit some twist without adverse effect. The individual filaments arefused together by means of a treatment with a suitable bonding agent,such as chloral hydrate or a multi-hydroxybenzene compound. First, asuitable nylon yarn is formed. The bonding agent, preferably insolution, is applied to the yarn. For convenience, the application ofthe bonding agent is made while the yarn is traveling longitudinally.Pressure of about 0.5 to 100 pounds per square inch and heat at about 50to 250 C. are applied to the yarn shortly after the application of thebonding agent to unite the filamentary material at points along thelength thereof and to induce evaporation and removal of the solvent ofthe bonding agent. The resultant straw-like structure possesses acoherency among the strands that is difficult to overcome without3,38%,fi25 Patented June 11, 1968 the performance of considerable work.Any residual bondinducing agent on the structure is not obnoxious anddoes not appreciably interfere with the dyeability of the fabric. Whilethe resultant straw-like structure can be used without furtherprocessing in the construction of fabric by braiding, plaiting,knitting, or weaving, additional but optional treatments may beemployed, such as washing, bleaching, dyeing, applying a softeningagent, or the like. Fabric made from the straw-like structure can beused in making hats, bags, shoe uppers, curtains, artificial grass,carpets, upholstery, etc.

The present invention will be further illustrated by reference to thedrawings wherein:

FIGURE 1 is a schematic perspective view of apparatus suitable for usein carrying out the method of the present invention;

FIGURE 2 is a perspective view of a straw-like structure of theinvention.

Referring now to FIGURE 1, a package of yarn 10 wrapped about bobbin 12is provided as a convenient source of a strand or bundle 14 of nylonfilaments. The bundle of filaments can be unrolled from the bobbin orwithdrawn overend. Alternatively, the bundle 14 can be advanced directlyfrom a filament-forming machine involving spinning and drawingoperations Without any intermediate package being formed. Thelongitudinal movement of the bundle can be controlled by the use of ayarn forwarding device. As shown, a pair of driven nipforming rolls 16are operated at a predetermined peripheral speed to deliver the bundleof filaments at a controlled rate and tension from the source of supplythereof. The bundle of filaments is then passed over the surface of anapplicator block 18, through Which sufiicient bonding agent is suppliedfrom metering pump 20 to wet the bundle. A simple wick arrangement mayreplace pump 20, but generally the pump gives much better control athigh speed operation.

Wetted bundle 14 is next passed a plurality of times around forwardingrolls 22 and 24, the axes of which are at a slight angle to provideproper advancement of the bundle 14, as is well known in the handling oftextile strands. A pinch roll 26 squeezes the bundle against roll 22,ensuring the flattening of normally rounded bundle of filaments into atape-like configuration as shown in FIGURE 2. At least one of rolls 22,24 and 26 is heated, to produce bonds between the parallel filaments andevaporate the bonding agent solvent, if any. It has been discovered thata superior and more straw-like article is produced if the bundle ispositively squeezed while heat is being applied; thus preferably one orboth of rolls 22 and 25 is heated in any conventional manner, as byincorporating an electrical heater within the rolls.

The finished flattened and bonded bundle is now taken up in an orderlyfashion, as on the schematically illustrated bobbin 28.

In FIGURE 2 it is seen that the bundle of filaments after thethermo-chemical treatment is in the form of a thin, fiat narrow stripbut that the individual filaments have not lost their identity. Theproduct possesses substantial longitudinal strength, as well as lateralstrength.

Dihydroxybenzene bond-inducing agents which can be employed includeresorcinol, hydroquinone, and pyrocatechol. The trihydroxybenzenesinclude pyrogallol, for example. Chloral hydrate has been found to giveexcellent results. The agents are not limited to the specificallyenumerated compounds since derivatives of the foregoing specificcompounds also can be used to develop a strong coherency between theindividual nylon filaments. Ordinarily, the bonding agents are solid atroom temperature; and for best results they are rendered fiuent beforebeing applied to the filaments in order that the filaments can be moreuniformly coated therewith. The compounds can be melted beforeapplication. However, the preferred procedure is to dissolve thecompounds in a suitable volatile solvent. Dihydroxybenzenes,trihydroxybenzenes, and chloral hydrate generally are readily soluble inwater, common alcohols (methanol, ethanol, etc.) and ethers (dimethylether and the like). These compounds dissolved in such solvents or othersolvents can be conveniently applied to the bundle of filaments in avariety of ways. The compounds can be sprayed, brushed, rolled, paddedor applied to the bundle of filaments in other similar ways. Theaddition of the compound can be uniform along the length of the bundleof filaments, or for economic reasons can be made only at certain spacedpoints along the length of the bundle.

It has been found that preferably a predetermined amount of the bondingagent is dissolved in methanol. A solution containing about 5 to 80percent bonding agent on a weight basis gives excellent results. Thepreferred concentration of the bonding agent in the solution is about 20to 60 weight percent. The concentration of the compound selected, as canbe perceived, will depend on many factors such as the method ofapplication, the proportion of the liquid picked up by the bundle offilaments, the bundle, etc. The temperature of the compound when appliedto the bundle of filaments is not too important. It has been found thatroom temperature is quite satisfactory as long as the compound is fluentwhen applied, although higher and lower temperatures can be employed.

It is necessary that the bundle of filaments picks up an amount of thebonding agent sufiicient to effect a strong coherency of the bundle offilaments. The amount of bonding agent applied to the bundle offilaments prior to heating can be varied within relatively broad limits,depending upon the thickness and weight of the structure, the nature andcharacteristics of the particular nylon filaments employed, theindividual properties of the bondinducing agent employed, the physicalproperties desired in the final straw-like structure, and so forth.Within the broader aspects of the invention from about 5 to 80 weightpercent bonding agent can be added on a dry basis.

As above indicated, it is necessary to heat the bundle of filamentscarrying the bond-inducing agents in order to effect a strong cohesionof the filaments. Heating of the filaments at an elevated temperature isfeasible by means of radiation, convection, or conduction. Preferably,the heat is supplied to the bundle of filaments by contact with a heatedsurface supplied by a heated rotating yarn forwarding roll or rolls. Inthis heating step the temperature of the strands is raised to about 50to 250 C., pref erably 50450 C., this being below the melting point ofthe nylon filaments. While heated, the bundle of filaments is positivelylaterally pressed in order to effect a better cohesion of the bundle offilaments and to shape the bundle into a straw-like structure. This canbe accomplished by pressing the bundle between two flat or roundedheated surfaces such as provided by nip-forming rolls. Pressures ofabout 0.5 to 100 pounds per square inch. are satisfactory, althoughpressures lesser or greater can be employed. The strength of theresultant structure generally rises up to a point where a higherpressure is used. Generally, excessive temperatures and pressures oughtto be avoided since they can induce an inferior product to be formed.However, prudent selection of optimum conditions to obtain the desiredproduct is not ditficult.

Finally, the resultant straw-like structure is cooled prior to anyfurther operation that undesirably would disturb the individualfilaments of which the structure is composed. The cooling can be quicklyaccomplished by directly applying a coolant thereto. However, merelyallowing the strands to reach equilibrium with room temperature is quitesatisfactory. After cooling, the resulting structure can be used in theconstruction of textile articles normally made of straw or artilicalstraw.

The filaments are composed of nylon. As is well known, nylon is along-chain synthetic polymeric amide which has recurring amide groups asan integral part of the main molecular chain, and Which is capable ofbeing formed into a filament in which the structural elements areoriented in the direction of the axis. Specific types of nylon fromwhich the filaments can be manufactured include nylon-66(polyhexamethylene adipamide), nylon-6 (polymeric E-aminocaproic acid),nylon-610 (polyhexamethylene sebacamide), nylon-4, nylon-7, nylon-11,etc., and various fiber-forming copolymers thereof.

The number of nylon filaments which can be bonded together by thepractice of the present invention to obtain the straw-like structure canrange from two to any suitable number of filaments including tow. Thecross section of the filaments may be round, but the cross section canbe multi-lobal, multi-faceted or the like. A bundle of filaments whereinthe filaments have a hexalobal cross sec tion can be shaped into a verydense straw-like structure since the lobes of the filaments will nestinto the con cavities of adjacent filaments.

The following examples illustrate specific embodiments of the presentinvention. It is understood that the invention is not limited thereto.All parts and percentages in the examples are by weight unless otherwiseindicated.

Example I A drawn continuous filament nylon-66 yarn composed offilaments and having a total denier of 840 was unwound from a bobbinthrough a tensioning device at a rate of feet per minute. The yarn wasmoved across an applicator issuing an aqueous solution containing 66weight percent chloral hydrate. The yarn then was passed 6 times arounda 4" diameter internally heated feed roll 22 maintained at 180 0.,having a peripheral speed of 180 feet per minute. A pinch roll 26squeezed the yarn sufiicient to flatten it to the configuration shown inFIG- URE 2. The yarn leaving the feed roll was wound up on a bobbin in aconventional way. The resultant structure had a straw-like appearanceand texture. The longitudinal strength of the structure was 8 grams perdenier. The lateral strength was also excellent.

Example H Instead of employing nylon-66 yarn, nylon-6 yarn was used. Thesame procedure as set forth in Example I was followed. Similarlyexcellent nylon artificial straw was obtained.

Example III nstead of employing chloral hydrate, a 35 percent aqeoussolution of pyrocatechol was employed as the bondinducing agent.Otherwise, the same procedure as in Example I was followed. Similarlyexcellent nylon artificial straw was obtained.

Example IV Instead of employing chloral hydrate, a 35 percent aqueoussolution of hydroquinone was employed as the bond-inducing agent.Otherwise, the same procedure as in Example I 'was followed. Similarlyexcellent nylon artificial straw was obtained.

Example V Instead of employing chloral hydrate, a 35 percent aqueoussolution of pyrogallol was employed as the bondinducing agent.Otherwise, the same procedure as in Example I was followed. Similarlyexcellent nylon artificial straw was obtained.

Example VI Instead of employing chloral hydrate, a 35 percent aqueoussolution of resorcinol was employed as the bondinducing agent.Otherwise, the same procedure as in Example I was followed. Similarlyexccllent nylon artificial straw was obtained.

In the place of water for rendering the bonding agent fluent, methanolethanol and diethyl ether can be used. Moreover, the use of a solventmay be omitted entirely.

There are a number of advantages afforded by the practice of theinvention. A non-woven, thin, fiat, narrow band or straw-like structureof nylon is provided. The procedure is simple and inexpensive. Thestraw-like structure can be braided, plaited or woven into articles ofmanufacture such as bags, hats, etc. Other advantages may be noted.

It is not intended that the invention be limited solely to the detailsof the embodiments set forth above. It will be recognized that numerousmodifications conforming to the spirit of the invention may be made.Therefore, it is intended that the invention be limited only by thescope of the following claim.

We claim:

1. Apparatus comprising in combination:

(a) first and second forwarding rolls having their axes at a slightangle to one another,

(b) a supply mechanism for feeding to said forwarding rolls a bundlecomprising a plurality of parallel drawn filaments, said bundle passinga plurality of times around said first and said second forwarding rolls,

(c) a pinch roll mounted adjacent and in contact with said firstforwarding roll for squeezing said bundle against said first forwardingroll,

References Cited UNITED STATES PATENTS 6/1936 Taylor 156-181 11/1961Sexsmith 161-170 1/1959 Coney et a1. 156-181 1/1964 Fox 156-441 X 9/1964Troelman et a1 156-180 12/ 1961 Stallard et a1 264-123 FOREIGN PATENTS5/1960 Germany.

EARL M. BERGERT, Primary Examiner.

HAROLD ANSHER, Examiner.

25 R. J. CARLSON, P. DIER, Assistant Examiners.

1. APPARATUS COMPRISING IN COMBINATION: (A) FIRST AND SECOND FORWARDINGROLLS HAVING THEIR AXES AT A SLIGHT ANGLE TO ONE ANOTHER, (B) A SUPPLYMECHANISM FOR FEEDING TO SAID FORWARDING ROLLS A BUNDLE COMPRISING APLURALITY OF PARALLEL DRAWN FILAMENTS, SAID BUNDLE PASSING A PLURALITYOF TIMES AROUND SAID FIRST AND SAID SECOND FORWARDING ROLLS, (C) A PINCHROLL MOUNTED ADJACENT AND IN CONTACT WITH SAID FIRST FORWARDING ROLL FORSQUEEZING SAID BUNDLE AGAINST SAID FIRST FORWARDING ROLL, (D) MEANSHEATING AT LEAST ONE OF SAID FIRST FORWARDING ROLLS AND SAID PINCH ROLLTO A TEMPERATURE BETWEEN 50* AND 200*C., (E) AND A METERING MECHANISMFOR APPLYING A BONDING AGENT TO SAID BUNDLE, SAID METERING MECHANISMBEING MOUNTED BETWEEN SAID SUPPLY MECHANISM AND SAID FORWARDING ROLLS.